From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Fri, 24 Apr 2015 01:24:27 +0000 (-0500)
Subject: Don't compare floating point numbers directly, but via std::fabs.
X-Git-Tag: v8.3.0-rc1~216^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=654eee910d2f139fe84fcc05502d6aedc019cfa4;p=dealii.git

Don't compare floating point numbers directly, but via std::fabs.
---

diff --git a/examples/step-42/step-42.cc b/examples/step-42/step-42.cc
index 8567b2429f..1453429020 100644
--- a/examples/step-42/step-42.cc
+++ b/examples/step-42/step-42.cc
@@ -952,14 +952,14 @@ namespace Step42
                ++face_no)
             if (cell->face(face_no)->at_boundary())
               {
-                if (cell->face(face_no)->center()[2] == p2(2))
+                if (std::fabs(cell->face(face_no)->center()[2] - p2[2]) < 1e-12)
                   cell->face(face_no)->set_boundary_id(1);
-                if (cell->face(face_no)->center()[0] == p1(0)
-                    || cell->face(face_no)->center()[0] == p2(0)
-                    || cell->face(face_no)->center()[1] == p1(1)
-                    || cell->face(face_no)->center()[1] == p2(1))
+                if (std::fabs(cell->face(face_no)->center()[0] - p1[0]) < 1e-12
+                    || std::fabs(cell->face(face_no)->center()[0] - p2[0]) < 1e-12
+                    || std::fabs(cell->face(face_no)->center()[1] - p1[1]) < 1e-12
+                    || std::fabs(cell->face(face_no)->center()[1] - p2[1]) < 1e-12)
                   cell->face(face_no)->set_boundary_id(8);
-                if (cell->face(face_no)->center()[2] == p1(2))
+                if (std::fabs(cell->face(face_no)->center()[2] - p1[2]) < 1e-12)
                   cell->face(face_no)->set_boundary_id(6);
               }
       }